RESUMEN
BACKGROUND: Our primary objective was to investigate the effects of three different endotracheal suctioning procedures on functional residual capacity (FRC). METHODS: Using a crossover design, postoperative cardiac surgery patients (n = 20) received three different suctioning methods in randomized order: closed suctioning during pressure-controlled ventilation, closed suctioning during volume-controlled ventilation, and open suctioning. FRC was measured before and 20 min after the intervention. RESULTS AND CONCLUSIONS: FRC is reduced in postcardiac surgery patients after suctioning, regardless of which method is used. Certain patients may have very pronounced changes of FRC. Routine FRC measurements could complement respiratory monitoring to optimize respiratory therapy.
Asunto(s)
Capacidad Residual Funcional , Respiración Artificial/métodos , Anciano , Estudios Cruzados , Femenino , Humanos , Mediciones del Volumen Pulmonar , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Presión , Succión , Cirugía Torácica/métodos , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Functional residual capacity (FRC) measurements may help to guide respiratory therapy. Using the oxygen washout technique, FRC can be assessed at bedside during spontaneous breathing. High repeatability, crucial for monitoring, has not been shown in ventilated patients. A large step change of inspiratory fraction of oxygen (FiO(2)) (DeltaFiO(2)) may impede the clinical use in patients ventilated with high FiO(2). We investigated the repeatability of FRC measurements and the impact of different DeltaFiO(2) on this repeatability. METHODS: The LUFU system (Draeger Medical, Luebeck, Germany) estimates FRC by oxygen washout, a variant of multiple-breath-nitrogen-washout during a fast DeltaFiO(2). In 20 postoperative cardiac surgery patients, FRC was measured in duplicate using DeltaFiO(2) of 0.1, 0.2, and 0.6. RESULTS: There were no differences between repeated measurements of FRC, neither using a DeltaFiO(2) of 0.1, 0.2 nor 0.6(Delta0.1: 2.62 L +/- 0.58, 2.62 L +/- 0.59, P = 0.995; Delta0.2: 2.70 L +/- 0.59, 2.66 L +/- 0.56, P = 0.258; Delta0.6: 2.61 L +/- 0.58, 2.59 L +/- 0.58, P = 0,639). Coefficients of variation were 6.6%, 5.6%, and 6.6%, respectively. CONCLUSIONS: FRC can be measured in ventilated patients using the oxygen washout technique with a clinically acceptable repeatability. Repeatability is not significantly influenced whether using a DeltaFiO(2) of 0.1, 0.2, or 0.6.
Asunto(s)
Pruebas Respiratorias , Procedimientos Quirúrgicos Cardíacos , Capacidad Residual Funcional , Inhalación , Oxígeno/análisis , Sistemas de Atención de Punto , Respiración con Presión Positiva , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
Proper oxygenation is critical to prevent hypoxia and myocardial ischemia in animals during pharmacological sedation. The authors compared the efficacy of two oxygen delivery masks during sedation and spinal anesthesia for knee surgery in sheep.
